Apparatus for heat-treating piston rings



March 29, 1949. M. w. MARIEN EI'AL 2,465,897

APPARATUS FOR HEAT-TREATING PISTON RINGS 2 Sheets-Sheet 1 Filed Sept. 15, 1947 INVENTORS MELVIN W. MARIEN CARL ELIPPMANN BY ATTORNEY.

M. w. MARIEN ETAL 2,465,897

APPARATUS FOR HEAT-TREATING PISTON RINGS March 29; 1949.

2 Sheets-Sheet 2 Filed Sept. 15, 1947 FIG. 3.

INVENTORS: MEuvlN W. MARIEN CARL E.L IPPMANN ATTORNEY.

Patented Mar. 29, 1949 APPARATUS FOR BEAT-TREATING PISTON RINGS Melvin W. Marion and Carl E. Lippmann, St. Louis, Mo., assignon to Ramsey Corporation, Wilmington, Del., a corporation of Delaware Application September 15, 1947, Serial No. 774,002

Our invention has relation to improvements in apparatus for heat-treating piston rings and it consists in the novel features of construction more fully set forth in the specification and pointed out in the claims.

The principal object of the invention is to heat the piston rings by electrical induction while they are held in proper shape by passage over a suitable form. The form is the essential part of a fixture on which the rings are loaded and continuously advanced past the induction coil to ultimately discharge on to a conveyor passing through a cooling medium.

We are aware that the heat-treating of piston rings is old in the art but as far as we know the continuous passage of piston rings over a suitable form while undergoing the heat treatment for the shaping of the rings is novel and together with the fixture employed forms the subject matter of the present invention. As far as we know it is also new to heat treat piston rings by electric induction.

The above objects, together with other advantages of the invention, will be better apparent from a detailed description thereof in connection with the accompanying drawings, in which:

Figure 1 isa side elevation of our improved fixture mounted in a suitable cooling tank (shown in section) through which a suitable conveyor passes for continuouslycarrying the rings away after treatment. Figure 2 is a side elevation taken at right angles to Figure 1 also showing the cooling tank in section and the conveyor for the rings. Figure 3 is a top plan of the fixture over which the rings are passed during heat treatment. Figure 4 is a horizontal cross section taken on the line 4-4 of Figure 2. Figure 5 is a perspective view of the bar for aligning the ring gaps as the rings pass over the loading fixture and Figure 6 isa perspective view of the lining bar for the rings as they pass on to a forming element where they undergo the heat treatment.

Referring to the drawings, F represents the fixture as a whole which comprises a loader l, a forming element 2, and upper lining bar 3 and a lower lining bar i. A lug 5 depends from the forming element 2 and is secured by a plate 6 to a standard l xtending upwardly from base 8. The base 8 is secured to a boss 9 on the bottom [0 of quenching tank T which has a fluid inlet pipe Ii and an overflow pipe i2 to maintain a constant level of water or other quenching medium. An endless conveyor C is carried by pulleys p', p, p, 12 mounted at each corner of the tank and passes under an idler p disposed within 2 Claims. (Cl. 266-4) the tank so that the conveyor will travel beneath the forming element 2 and receive the rings as they discharge therefrom and carry them through the cooling medium to be ultimately discharged from the conveyor in any well-known manner.

The essence of the invention is the fixture F over which rings R are passed and subjected to the heat of an induction coil E which surrounds the forming element 2 in sufilciently spaced relation to permit the free passage of the rings over the element 2 and within the coil E. The induction coil E is connected to a source of electrical energy represented by line wires 20, w. The forming element 2 comprises a lower cylindrical portion a, and an upper frustro conical section b, upon the latter of which is disposed, and which we choose to term. a loader i held in place thereon by a center pin 63 disposed in a socket it in the forming element and a socket it in the loader. The forming element 2 is provided with a longitudinally disposed slot is and the loader is provided with a slot H to register with the slot 16, the lower part of slot it being enlarged as shown at ill to register with the slot iii in the forming element. The liner bar 3 is secured in slot I! by screws it and the lower lining bar i is secured in slot it? by screws it, this latter bar extending upwardly into the enlargement ll of slot 87. it will be observed that the bar 3 has a rib 20 extending outwardly from it, being tapered outwarclly from the top to the bottom of said bar, and articulating with the tapered upper end 2i of rib 22 extending laterally from the lower lining bar t. Thus, it will be apparent that the ribs iii and 25 are co-extensive and gradually taper outwardly until they come opposite to the cylindrical portion a of forming element 2, opposite the entire extent of which the rib 22 is of uniform width. The purpose of this tapering construction of the combined forming bars is to facilitate the disposition of the rings on the loader i with their gaps embracing the liner bar. As the rings are forced downwardly over the loader if their gaps will encounter the gradually increasing width of the liner bar until the rings enter upon the form ing element 2 at which time the gaps will have been expanded to their normal dimension and the rings will have been properly shaped for the heat treatment about to follow.

The forming element 2 may be of any desired shape that ultimately is to be imparted to the piston rings. 0f course, the shape generally sought is that which will give the rings uniform radial tension in action. Heretofore, this shape has generally been accomplished by making individual ring castings. Under our improved meth d the rings may be cut from a hollow cylinder and subsequently shaped under heat on the desired form.

It will be observed that the forming element 2 is of solid metallic construction and will, therefore, store up heat from the induction coli 12. Therefore, as the rings pass over the element 2 they will be exposed to both the heat of the coil on the outside and the heat of the element on the inside.

It ls quite obvious that many methods of advancing the ring column over the fixture F may be utilized other than a mere manual feeding thereof. Such feed mechanism forms no part of the present invention and is not shown in detail. However, B indicates conventionally a plunger of any available automatic feed.

Having described our invention, we claim:

1. A fixture for heat-treating split piston rings comprising a loader, a forming element in line therewith, the loader and the forming element having lining bars for alining the gaps of the rings, and an induction coil contiguous to the forming element.

MELVIN w. MARIEN. CARL n. LIPPMANN.

REFERENCES crmn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 606,675 Marcy July 5, 1898 1,619,296 Graves Mar. 1, 1927 1,702,985 Twyman Feb. 19, 1929 2,183,358 Six Dec. 12, 1939 2,336,462 Bristow Dec. 14, 1943 

